you shall aim for at least lv 5/5* in CE English if you are intended to study in the UK ... and 5A1B1C1F is not good enough if you are aiming for LSE/Oxbridge.

except for medicine which you'll need to obtain an A/A* in GCSE Biology and Physics ...

well like i said it'd be an exceptional case as candidates should, normally, continues to do well in A-Level, preceded by a successful outcome in GCSE (virtually all those who are doing law/medicine at Oxbridge got a string of A/A* under their belt ...)